Vehicle and powertrain designers seek to improve efficiency and vehicle fuel economy. One aspect of improving fuel economy includes reducing energy losses through a transmission assembly. Automatic transmissions are complex assemblies, incorporating fluid coupling, multiple gear sets, and other sources of inefficiency. Spin loss is a term known in the art as a measure quantifying the torque lost in a transmission assembly: torque applied by the engine minus spin loss equals the torque output by the transmission assembly. Reducing spin loss in a transmission assembly reduces fuel required for the engine to create the same torque output in the transmission assembly. Testing has shown that spin loss is highly dependent upon the operating temperature of the transmission assembly. Transmission assemblies are designed to operate optimally at a particular temperature corresponding to the steady state conditions within an operating vehicle. Spin losses attributable to a transmission operating at temperatures below the steady state condition may be reduced by bringing the transmission up to temperature more quickly.